Mariah Carey's brother fears she will 'die like Whitney Houston' as he claims the pop star is addicted to alcohol and prescription drugs

Mariah Carey's brother fears her drinking will kill her and claims he has never seen her sober.

The Hero hitmaker's sibling Morgan - who hasn't directly spoken to the singer in two years - fears the star is unable to care for her four-year-old twins Moroccan and Monroe because he believes she is trying to numb her problems with wine and champagne.

Alleging she has been a heavy drinker since suffering from mental health problems in 2001, Morgan told the National Enquirer magazine: 'Mariah was drinking through her pregnancy - even while she was nursing.

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Disturbing claims: Mariah Carey's brother Morgan Carey fears her drinking will kill her and claims he has never seen her sober, the singer pictured in May in New York

'I can't say that I have ever been around her when she was sober, and that's very scary.'

Morgan also claimed his 45-year-old sister takes a daily cocktail of medications including Zyprexa, Ativan and Depakote, and fears she will 'die like Whitney Houston'.

He added: 'She does not have a support system, and she is not mentally capable.'

Estranged: Morgan claims he has not seen his sister in two years, pictured in 1991

Morgan is concerned the Without You singer has 'pushed away the only people who've been trustworthy' and will blame her entourage if anything does happen to her.

He said: 'If my sister turns up dead ... I'm not going to look the other way! Anyone who's filling her glass is jeopardising her life!'

Reps for Mariah Carey declined DailyMail.com's request for comment on these claims.

He says it was a sham: Morgan went on to allege that the father of Mariah's twins, Nick Cannon, married her for her money, the family pictured in October 2012 at the Santa Monica Pier in California

Mariah's brother also branded her estranged husband Nick Cannon a 'crock of s**t' who wasn't good for his sister and was only interested in money.

He said: 'Nick listened to people who said, "Get with Mariah, she thinks you're cute, have kids and ride it to the bank." Nick was there for the cash from day one. He doesn't give a damn about Mariah.

'Nick took tremendous advantage of her and continues to do so.'

DailyMail.com has contacted reps for Nick Cannon regarding these claims.